Surprised to see this one here, but this is also my answer. Been awhile since I read the book, but I seem to remember the other big point being the whole blood transfusions thing from the movie wasn’t there, that was all made up bullshit. In fact, “Rita” had not lost her power, they were going through overlapping loops which is so much cooler, but I guess was deemed too confusing for audiences so we got that schlocky Hollywood ending instead.